Is cross-posting wrong (to an external site)?

Question

I made a question at Stack Overflow long ago and also posted the same question in a non-Stack Exchange website (Xtreme VB Talk). The question was answered, Combining two PNG images into one image using .NET.

According to the answer, I shouldn't have cross-posted between Stack Overflow and XtremeVBTalk, because

it increases the probability that wires will get crossed and everyone will waste time.

But I'm not sure why is that wrong. You see, I simply see Stack Overflow and XtremeVBTalk as two different communities with different users. So posting the question in both sites would just give me more answers. And if I got the answer in one of them, I would report back to the other site and let everyone know (and perhaps someone else would be benefited as well). I really doubt it is a waste of time - the more input, the better. The fact that someone was a user in both websites is simply a coincidence.

I realize that Meta Stack Exchange question Is cross-posting a question on multiple Stack Exchange sites permitted if the question is on-topic for each site? exists, but apparently it involves cross-posting within Stack Exchange sites, but this is about external websites instead.

I also realize that I was told that as "advice" (since my question was not flagged or anything), but well, I am now curious: Why would anyone consider this a bad practice?

Answer 1

I like the way how this is addressed at Java Ranch:

Be Forthright When Cross Posting To Other Sites

...keep in mind that this is not generally in the interests of the posters who might be responding to your posts - those folks may find they've wasted their time. You certainly don't want to annoy those you want to help you, so you might want to make the experience as painless as possible.

The best way to do something like this (without ticking people off) would be to let people know upfront that the crossposting is occurring. This makes the most sense if there's a respectable delay between posting in one forum and another, e.g:

"I posted this question the other day in SomeOtherForum.com [link], but wasn't able to get a good answer, so now I'm asking here..."

A responsible netizen might also post a followup in SomeOtherForum.com letting people there know if a better answer is found.

Answer 2

I simply see SO and XtremeVBTalk as two different communities with different users. So making the question in both sites would just give me more answers.

Ideally, but in practice you're probably going to get mostly the same answers twice, which means twice as many people had to take the time to answer. Worse, it tends to be the case that once somebody's problem is solved on one forum, they immediately start ignoring their question everywhere, because they've got their solution. Meanwhile, people keep trying to help on these other forums, even though the OP is ignoring the post completely now

If you're going to cross-post all the answers as they come in it's probably ok, but most people don't bother, and having a bunch of communities work on your problem simultaneously is probably unnecessary unless it's particularly difficult

Answer 3

Personally--and I don't claim to speak for anyone else--it demotivates me to even try to help.

It feels like you either

1. don't expect us to succeed
2. don't value what we might have to offer
3. are only posting it for the points

This may not be logical, but it is how I respond.

Take that for what you will.

Answer 4

From the economic viewpoint, if you post the same message to 2 forums and a person is subscribed to both, that person will receive 2 identical incoming messages. Reading them wastes time and is annoying, especially if a user needs to go from the email program to the web to read the message. For example, Liferea, a desktop feed reader, marks all identical messages as read if any of them is read by a user. Hence this issue is even recognized in some UIs.

The damage from cross-posting described above can be remedied by a technology that shows a user all identical messages as one message and one set of comments. Then a whole slump of bureaucracy mentioned in the answers goes away:

• Thinking and arguing which forum is the most appropriate for a message. And this is hard, trust me, because there is no objective criteria to accomplish this.
• Moving a message between forums.
• Waiting between posting a message on one forum and another.
• Notifying forum users about cross-posting and apologizing for it.
• Copying answers or linking to answers from a forum to another forum. Checking whether the answer is given on another forum.

Implementing such a technology requires not only a tech talent, but a political talent as well. Such a technology blurs borders between forums, but forums compete with each other, not cooperate. It's like persuading countries to join in a trade agreement. Actually, I can describe you an algorithm and a network protocol right now, but I have no means of implementing it.